This invention is generally directed to imaging members and to processes thereof. More specifically, the present invention is directed to layered photoconductive imaging members comprised of a supporting substrate, a photogenerating layer, and thereover a charge transport layer comprised of charge transport molecules dispersed in a fluorinated polycarbonate resin binder. Advantages associated with the imaging members of the present invention include wear resistant charge transport layers, life extension of the imaging members by, for example, 50,000 imaging cycles in xerographic imaging devices, such as the Xerox Corporation 5090, resistance to abrasion during cleaning, especially with wiper blades, and by contact with carrier particles, efficient and effective cleaning, and the like. The photoresponsive imaging members of the present invention can also, for example, contain situated between the photogenerating layer and a hole transporting layer, or situated between the photogenerating layer and a supporting substrate with a charge transport layer in contact with the photogenerating layer, a photoconductive composition comprised of, for example, bisazo photogenerating pigments.
Layered imaging members are known. These imaging members can be comprised of photogenerating layers, and in contact therewith charge transport layers comprised of aryldiamines, reference U.S. Pat. No. 4,265,990, the disclosure of which is totally incorporated herein by reference. Layered imaging members with charge transport arylamines dispersed in resin binders, like polycarbonates, such as MAKROLON.RTM., are known. Examples of highly insulating and transparent resinous components or inactive binder resinous material for the transport layer include materials such as those described in U.S. Pat. No. 3,121,006, the disclosure of which is totally incorporated herein by reference. Specific examples of known organic resinous materials include polycarbonates, acrylate polymers, vinyl polymers, cellulose polymers, polyesters, polysiloxanes, polyamides, polyurethanes and epoxies as well as block, random or alternating copolymers thereof. Preferred electrically inactive binder materials are polycarbonate resins having a molecular weight of from about 20,000 to about 100,000 with a molecular weight in the range of from about 50,000 to about 100,000 being particularly preferred. The materials usually preferred as electrically inactive resinous are poly(4,4'-dipropylidene-diphenylene carbonate) with a weight average molecular weight of from about 35,000 to about 40,000 available as LEXAN.TM. 145 from General Electric Company; poly(4,4'-isopropylidene-diphenylene carbonate) with a weight average molecular weight of from about 40,000 to about 45,000 available as LEXAN.TM. 141 from General Electric Company; a polycarbonate resin having a weight average molecular weight of from about 50,000 to about 100,000 available as MAKROLON.RTM. from Farbenfabricken Bayer AG; and a polycarbonate having a weight average molecular weight of from about 20,000 to 50,000 available as MERLON.RTM. from Mobay Chemical Company. Generally, the resinous binder contains from about 10 to about 75 percent by weight of the active material corresponding to the foregoing formula, and preferably from about 35 percent to about 50 percent of this material. Examples of binder material for the photogenerating layer include poly(vinyl acetals), polycarbonates as mentioned herein, polyesters, polyvinyl carbazole, and the like. Typical effective amounts of binder can be selected including, for example, from about 5 to about 95, and preferably from about 10 to about 70 weight percent. These imaging members while suitable for their intended purposes can possess a number of disadvantages, such as being substantially nonresistant to cleaning, and subject to abrasion after about 25,000 imaging cycles, thereby causing undesirable copies with reduced quality. These imaging members can also be difficult to clean or require complex and expensive cleaning systems to achieve adequate cleaning. These and other disadvantages are avoided, or minimized with the imaging members of the present invention.
Imaging members with certain bisazo pigments are known, reference for example U.S. Pat. No. 3,898,084, which discloses, for example, the azo pigment Chlorodiane Blue in a photoconductive imaging member. Further, there are disclosed in the prior art layered photoresponsive devices, including those comprised of separate generating layers, and transport layers as described in U.S. Pat. No. 4,265,990, the disclosure of which is totally incorporated herein by reference; and overcoated photoresponsive materials containing a hole injecting layer overcoated with a hole transport layer, followed by an overcoating of a photogenerating layer; and a top coating of an insulating organic resin, reference U.S. Pat. No. 4,251,612. Examples of photogenerating layers disclosed in these patents include trigonal selenium and phthalocyanines, while examples of transport layers include certain diamines as mentioned therein.
U.S. Pat. No. 4,713,307, the disclosure of which is totally incorporated herein by reference, discloses photoconductive imaging members containing a supporting substrate, certain azo pigments as photogenerating materials, and a hole transport layer that preferably contains an aryl diamine compound dispersed in an inactive resinous binder, such as a polycarbonate.
U.S. Pat. No. 4,797,337, the disclosure of which is totally incorporated herein by reference, discloses a photoconductive imaging member comprising a supporting substrate, a hole transport layer, and a photogenerating layer comprising specific disazo compounds.
In a patentability search report the following U.S. patents were recited: No. 4,772,526, which discloses a reusable electrophotographic imaging element having a photoconductive surface layer in which the binder resin comprises a block copolyester or copolycarbonate having a fluorinated polyether block, see the Abstract for example; No. 4,030,921, which discloses an electrophotographic photosensitive material including a conductive backing and a photosensitive layer being formed of a photoconductive material, a resin binder, and a fluorine containing resin which can be a polymer or copolymer having a fluorine contained monomer as its structural units and is preferably soluble in a solvent, see the Abstract for example; Pat. No. 4,663,259, which discloses an electrophotographic sensitive member comprising a conductive substrate, a charge transport layer and a charge generation layer wherein said charge generation layer is superimposed on said charge transport layer and said charge generation layer contains particles of certain fluorine containing resins, see the Abstract for example; Nos. 4,007,043; 4,063,947; 4,784,928; 4,803,140; 4,863,823; 4,869,982; and as background of collateral interest 4,232,101; 4,677,044; 4,724,195 and 4,734,347.
Additional references illustrating layered organic electrophotographic photoconductor elements with azo, bisazo, and related compounds, and charge transport layers dispersed in certain resin binders, such as polycarbonates, include U.S. Pat. No. 4,390,611, U.S. Pat. No. 4,551,404, U.S. Pat. No. 4,596,754, Japanese Patent 60-64354, U.S. Pat. No. 4,400,455, U.S. Pat. No. 4,390,608, U.S. Pat. No. 4,327,168, U.S. Pat. No. 4,299,896, U.S. Pat. No. 4,314,015, U.S. Pat. No. 4,486,522, U.S. Pat. No. 4,486,519, U.S. Pat. No. 4,555,667, U.S. Pat. No. 4,440,845, U.S. Pat. No. 4,486,800, U.S. Pat. No. 4,309,611, U.S. Pat. No. 4,418,133, U.S. Pat. No. 4,293,628, U.S. Pat. No. 4,427,753, U.S. Pat. No. 4,495,264, U.S. Pat. No. 4,359,513, U.S. Pat. No. 3,898,084, U.S. Pat. No. 4,830,944 and U.S. Pat. No. 4,820,602.
U.S. Pat. No. 4,755,443 discloses a photoreceptor for electrophotography which comprises a charge carrier generating material and charge transport material wherein one charge generating material is a metal phthalocyanine or a metal-free phthalocyanine. The layer containing the generator material also contains an organic amine. Other carrier generating substances can be used in combination with the phthalocyanine generator material, including azo pigments, anthraquinone dyes, perylene dyes, polycyclic quinone dyes, and methine stearate pigments.
U.S. Pat. No. 4,424,266 discloses an electrophotographic photosensitive element having a conductive support and a photosensitive layer comprising a carrier generating phase layer containing a carrier generating material selected from the group consisting of perylene dyes, polycyclic quinones, and azo dyes, and a carrier transporting phase layer containing a hydrazone carrier transporting material.
U.S. Pat. No. 4,808,506, the disclosure of which is totally incorporated herein by reference, discloses a layered photoresponsive imaging member which comprises a supporting substrate, an imidazole perinone comprising components with a mixture of cis and trans isomers of a specific formula, including trans indanthrene Brilliant Orange, cis indanthrene Bordeauxs Red, bis-(4,5-dimethyl)benzimidazole perinone and bis-2,3-naphthimidazole perinone, and an aryl amine hole transport layer comprised of aryldiamines dispersed in a number of resin binders, such as polycarbonates.